Visualization method to predict the nucleophilic asymmetric induction of prochiral electrophiles.

[reaction: see text] This work focuses on the development of a simple technique to accurately predict and visualize the diastereoselectivity of ketone, aldehyde, and allyl chloride reductions by mapping electrostatic potential onto the frontier molecular orbital involved in the reduction. A distinct difference of electrostatic potential on the faces of the carbonyl can be used to predict the face of nucleophilic attack with a high level of accuracy.

Characterization and application of sodium di(2-ethylhexyl) sulfosuccinate and sodium di(2-ethylhexyl) phosphate surfactants as pseudostationary phases in micellar electrokinetic chromatography.

Sodium di(2-ethylhexyl) sulfosuccinate (DOSS) and sodium di(2-ethylhexyl) phosphate (NaDEHP) surfactants, with double alkyl chains and negatively charged headgroups, were characterized using fluorescence quenching, densitometry, and tensiometry techniques to determine their aggregation number, partial specific volume, and critical aggregation concentration. These two surfactants were then applied as pseudostationary phases in micellar electrokinetic chromatography (MEKC) for separations of alkyl phenyl ketones. The aggregation number of NaDEHP was found to be more than two-fold higher than that of DOSS. The partial specific volumes of NaDEHP and DOSS were found to be 0.9003 and 0.8371 mL/g, respectively. The critical aggregation concentrations are 5.12 and 1.80 mM for NaDEHP and DOSS, respectively. The DOSS surfactant provided a wider separation window and had a greater hydrophobic environment than the NaDEHP surfactant under the MEKC experimental conditions studied.

Molecular springs, muscles, rheostats, and precessing gyroscopes: from review to preview.

The concepts of molecular springs and gyroscopes have existed for some time, and there have been numerous reports published about these fascinating topics. Here we describe our interest in this topic, reviewing our initial progress. This is not a complete story, rather an offering of synthetic strategies, interesting molecular structures, observations, and possibilities. In many cases, the "properties" component of the structure-property relationship for a given compound is the result of a computational prediction. Given the present state of theoretical chemistry, a computer's predictive power can far exceed that which can be presently accomplished by existing experimental analytical means. The theoretical results reported here allude to intriguing possibilities. Hopefully, this intrigue will help catalyze the development of definitive, albeit rather esoteric, single-molecule analytical experiments. The intentionally speculative nature of this review is intended to stimulate new challenges for and perspectives from those in related fields of interest; hopefully presenting a preview of what is to come.